Vehicles are more commonly including electric powertrains to improve fuel economy and reduce emissions. Electric powertrains utilize a traction motor to power driven wheels of the vehicle. The traction motor may be used in conjunction with an internal-combustion engine in hybrid vehicles. The traction motor is powered by a traction battery, fuel cell, or other electrical power source.
Electric motors produce usable torque over a broader range of speeds than engines and typically do not require a multi-speed gearbox. Instead, electric powertrains typically include a one-speed gearbox that reduces shaft speed and multiplies torque for the driven wheels. A typical one-speed gearbox includes an input shaft fixed to motor, an output element (such as a ring gear), and a layshaft meshing between the input shaft and the output element.